Improvement in metallic cartridges



J'. MERWIN.

METALLIC-CARTRIDGE. No. 175,293 Patented March 28,1876.

JOSEPH MERWIN, OF BROOKLYN, NEW YOBK.

IMPROVEMENT IN METALLIC CARTRIDGES.

Specification forming part of Letters Patent No. 175,293, dated March 28, 1876; application filed April 28, 1874.

To all whom it may concern:

Be it known that I, JOSEPH MERWIN, of Brooklyn, Kings county, State of New York, have invented an Improvement in Flange- Headed Cartridge-Shells for Breech-Loading Fire-Arms, and particularly revolver-s, of which the following is a specification,reference being had to the accompanying drawings forming part thereof, in which Figure 1 is a side view of the shell, and Fig. 2 is a similar view, with the lower portion of the butt in section, to bring into view the peculiar construction of the base-plate of the shell.

This invention relates to that class of metalcased cartridges for revolvingfire-arms, in which the priming is contained in the space within a flange or annular projecting base of the head of the shell; and consists in forming the central portion of the wall of the closed end or butt into a cone projecting inward, whereby the said wall has greater strength to resist the force exerted by the explosion of the cartridge, tending to drive the head of the shell back against the recoil;plate of the pistol, and thereby bind the cylinder and prevent its full and easy revolution.

It is well known that in the use of this description 0t ammunition in revolving firearms it frequently occurs that the cylinder becomes set, so as to be incapable of being revolved or started by the mechanism of the pistol provided for the purpose, occasioned by the wall of the butt of the cartridge being forced back against the recoil-plate of the revolver, and this result is most likely to occur in the use of flange-headed cartridges, that contain their priming in the annular space within the flange, both because these eartridges contain necessarily a larger amount of fulminate than do center-fire cartridges,

and because the base wall, being increased in diameter by the formation of the flange or annular projection, ofl'ers less resistance to the force of the exploded charge.

My invention is intended to obviate this difficulty. It is evident that by carrying the center of the base-wall inward so as to form a cone, as shown in Fig. 2, great additional strength will be imparted to the head; and a practical trial of this form of head has demonstrated that the heaviest practicable charges may be used in this description of cartridges without any liability of forcing the head back against the recoil-plate ot' the pistol, so as to occasion any binding of the cylinder or any obstruction to its free and easy revolution.

I am aware that center-fire cartridges are made, in which a receptacle is provided in the center of the head, by forcing the metal inward at the center, thus formin g a cup or recess with parallel walls of greater or less depth; also, that the wall of the closed end has been forced inward into aconcavo-convex form in shells made without an annular projecting base. I do not claim cartridge-shells thus formed, intending to confine myself to cartridges formed in the specific form here described and shown.

I claim- A metallic cartridge-case made With an annular projecting base containing the priming, and with the wall of the head or closed end formed into a cone projecting inward, substantially as and for the purpose described.

WVitness my hand this Zlth day of April, 1874.

JOSEPH MERWIN.

Witnesses:

B. S.'OLARK, 1. S. MACKENZIE. 

